title: Intracerebral hematomas disappear on T2*-weighted images during normobaric oxygen therapy.
abstract: OBJECTIVE
  The aim of the present study was to investigate the effects of normobaric oxygen (NBO) therapy on T2*-weighted images of intracranial hemorrhages (ICHs).
  
  
  METHODS
  Two common models of ICH were performed in mice, and longitudinal T2*-weighted images of the hematomas were acquired under normoxia or NBO. The effects of NBO were also investigated on perfusion-weighted imaging, susceptibility-weighted imaging, and molecular imaging of vascular cell adhesion molecule-1 after ICH. Last, we performed neurological testing, including neuroscore, actimetry, and gait analysis (Catwalk), to study the influence of NBO on neurological outcome of mice presenting ICH.
  
  
  RESULTS
  Our results demonstrated that NBO, even during a short period of time, dramatically reduces the sensitivity of T2*-weighted imaging to detect ICH. Moreover, we provide evidence that the disappearance of ICH on T2*-weighted imaging could be used to improve accuracy of perfusion-weighted imaging and to allow molecular imaging after ICH. Importantly, a 30-minute NBO preparation 24 hours after ICH onset does not influence neurological outcome.
  
  
  CONCLUSIONS
  We provide an experimental demonstration that NBO significantly affects T2*-weighted imaging in ICH. Although this phenomenon could lead to inaccurate assessment of ICH volume, it could also be safely used to allow perfusion-weighted imaging and molecular imaging.
authors.affiliation: From the Inserm, UMR-S U919, Serine Proteases and Pathophysiology of the Neurovascular Unit, GIP Cyceron, University Caen Lower-Normandy, Caen, France (T.G., C.G., A.M., V.A., M.R., E.E., D.V., M.G.); and Department of Neurosurgery (T.G., E.E.), Department of Anesthesiology and Critical Care Medicine (M.H.), and Biostatistics and Clinical Research Unit (M.R.), Caen University Hospital, Caen, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gaberel
authors.forename: Clement
authors.initials: C
authors.lastname: Gakuba
authors.forename: Marie
authors.initials: M
authors.lastname: Hebert
authors.forename: Axel
authors.initials: A
authors.lastname: Montagne
authors.forename: Veronique
authors.initials: V
authors.lastname: Agin
authors.forename: Marina
authors.initials: M
authors.lastname: Rubio
authors.forename: Evelyne
authors.initials: E
authors.lastname: Emery
authors.forename: Denis
authors.initials: D
authors.lastname: Vivien
authors.forename: Maxime
authors.initials: M
authors.lastname: Gauberti
mesh_terms: D000818:Animals; D001921:Brain / Q000473:pathology*; D020300:Intracranial Hemorrhages / Q000097:blood / Q000473:pathology* / Q000628:therapy; D008279:Magnetic Resonance Imaging; D051379:Mice; D010100:Oxygen / Q000097:blood; D010102:Oxygen Inhalation Therapy; D016896:Treatment Outcome
chemical_list: D010100:Oxygen
keywords: behavior therapy; cerebral hemorrhage; magnetic resonance imaging; molecular imaging